The present invention relates to a turbomachine arrangement, including a housing, a turbo-expander comprising an expander rotor, a turbo-compressor comprising a first compressor rotor, and a shaft, which is rotatably mounted on the housing. The shaft connects the expander rotor to the first compressor rotor.
Known turbomachine arrangements, sometimes referred to as “companders” (compressor-expanders), are used during the expansion of a fluid (in cooling circuits, for example) for recovering pressure energy in the expander and making this usable for the compressor which is coupled to the expander. Since the quantity of energy recovered from the expander is usually not sufficient for operating the compressor, it is necessary to apply additional energy. For this purpose, the shaft that couples the expander to the compressor can be additionally driven. This has the disadvantage, however, that neither the compressor nor the expander can always be operated in the optimal speed range.
Alternatively, the compressor and the expander also can be operated separately from one another and can be coupled to each other only indirectly. Thus, the energy recovery potential is reduced due to additional conversion losses. In addition, the fact that there are two separate systems results in a need for a greater amount of maintenance and space.